The present invention relates to a device for shielding of harmful radiation, particularly of X-rays, in electron bombardment or irradiation of materials on a sheet, especially a paper sheet. The device is especially suitable for shielding from radiation formed in electron bombardment hardening of printed inks on a paper sheet.
An apparatus and method for shielding of an inert zone-electron bombardment of materials on a moving sheet is described in German Published Patent Application DE-OS 29 19 529. In this apparatus, among other features, deflection devices are provided to guide the sheets at a predetermined angle to the direction of the inlet collimation and to allow it to issue at a predetermined angle to the direction of the outlet collimation. The escape of the scattered or stray radiation can be avoided because of these deflection devices. The guiding of the sheets is performed for example by rolls or other rotating components.
In the apparatus and method of DE-OS 29 15 529 it is disadvantageous that the smear effect appearing on the surface of the sheet to be dried and double impressions arising because of a a remaining adhering surface layer on the rolls or rotating components leads to a quality reduction in the product.
German Published Patent Application DE-OS 3,411,752 describe means for feeding in and guiding out a sheet-like material each comprising two rotatably mounted driven rolls positioned above each other and contacting each other over their respective lengths. The rolls forming the input and output device each are associated with a moistening means film of a reliable moistening device separating the printed ink on the sheet of material and the roll surface. The drying chamber can be fed a sheet of material freshly printed on blank paper and on the back from any arbitrary direction free of smears with the device described in this reference. However the disadvantages of this feed device are a comparatively large engineering expense because of the required moistening device and rolls.